Map non allied unit at tgt tile to ANEK system
Have the action not enabled explanation system detect that a non allied unit at the target tile is blocking an action when unit_move_to_tile_test() returns MR_DESTINATION_OCCUPIED_BY_NON_ALLIED_UNIT.
Have the action not enabled explanation system detect that a non allied unit at the target tile is blocking an action when unit_move_to_tile_test() returns MR_DESTINATION_OCCUPIED_BY_NON_ALLIED_UNIT.